Static Single Channel Per Carrier (SCPC) bandwidth allocation has limitations in a dynamic environment when the bandwidth required by terminals changes. Most users of the static SCPC require a minimum Committed Information Rate (CIR) with additional dynamic bandwidth usage in real-time.
SCPC refers to a Very Small Aperture Terminal (VSAT) satellite transmission system that uses a separate carrier for each of its channels. In an SCPC system, transmissions are sent to a satellite continuously on a single satellite carrier. The satellite signal is received at a single location, in the case of a point-to-point system, or at many locations in a broadcast system, providing hubless connectivity among multiple sites. to using a single signal at a given frequency and bandwidth. Most often, this is used on broadcast satellites to indicate that radio stations are not multiplexed as subcarriers onto a single video carrier, but instead independently share a transponder.
As illustrated in FIG. 3A, prior art SCPC implementations use employ a large number of closely spaced subcarriers that are transmitted in parallel using either a static allocation or a feedback based dynamic allocation. The prior art dynamic allocation feedback system wastes bandwidth for the feedback and is slow as the control loop for the feedback may traverse over satellite transmission hops. Moreover, frequency bandwidth reallocation disturbs every other SCPC terminals in the network as a bandwidth increase for a terminal needs a reduction elsewhere in the system.